Power and optical fiber interface

ABSTRACT

A power and optical fiber interface system includes a housing having an interior. A cable inlet is configured to receive a hybrid cable having an electrical conductor and an optical fiber. An insulation displacement connector (IDC) is situated in the interior of the housing configured to electrically terminate the conductor, and a cable outlet is configured to receive an output cable that is connectable to the IDC and configured to output signals received via the optical fiber.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation application of U.S. Non-Provisionalpatent application Ser. No. 17/567,331, filed Jan. 3, 2022, which is acontinuation application of U.S. patent application Ser. No. 16/704,964,filed Dec. 5, 2019, now U.S. Pat. No. 11,215,776, issued Jan. 2, 2022,which is a continuation application of U.S. Non-Provisional patentapplication Ser. No. 15/985,068, filed May 21, 2018, now U.S. Pat. No.10,502,912, issued Dec. 10, 2019, which is a continuation of U.S.Non-Provisional patent application Ser. No. 15/373,709, filed Dec. 9,2016, now U.S. Pat. No. 9,977,208, issued May 22, 2018, which is acontinuation application of U.S. Non-Provisional patent application Ser.No. 14/331,873, filed Jul. 15, 2014, now U.S. Pat. No. 9,557,505, issuedJan. 31, 2017, which claims the benefit of U.S. Provisional PatentApplication Ser. No. 61/846,392, filed Jul. 15, 2013 and is acontinuation-in-part of PCT Patent Application No. PCTUS2014/030969,filed Mar. 18, 2014, which claims the benefit of U.S. Provisional PatentApplication Ser. No. 61/802,989, filed Mar. 18, 2013. The disclosures ofall of the above-mentioned patent applications are hereby incorporatedby reference in their entireties.

BACKGROUND

The present disclosure relates generally to hybrid optical fiber andelectrical communication systems.

Rapid growth of portable high-speed wireless transceiver devices (e.g.,smart phones, tablets, laptop computers, etc.) continues in today'smarket, thereby creating higher demand for untethered contact. Thus,there is growing demand for integrated voice, data and video capable ofbeing transmitted wirelessly at data rates of and faster. To provide thebandwidth needed to support this demand will require the cost effectiveand efficient deployment of additional fixed location transceivers(i.e., cell sites or nodes) for generating both large and small wirelesscoverage areas. Fiber optic technology is becoming more prevalent asservice providers strive to deliver higher bandwidth communicationcapabilities to customers/subscribers. The phrase “fiber to the x”(FTTX) generically refers to any network architecture that uses opticalfiber in place of copper within a local distribution area. Example FTTXnetworks include fiber-to-the-node (FTTN) networks, fiber-to-the-curb(FTTC) networks, fiber-to-the-home (FTTH), and more generally,fiber-to-the-wireless (FTTW).

SUMMARY

In accordance with aspects of the present disclosure, examples of apower and optical fiber interface system include a housing having aninterior. A cable inlet is configured to receive a hybrid cable havingan electrical conductor and an optical fiber. An insulation displacementconnector (IDC) is situated in the interior of the housing configured toelectrically terminate the conductor, and a cable outlet is configuredto receive an output cable that is connectable to the IDC and configuredto output signals received via the optical fiber.

In accordance with further aspects of the disclosure, examples of thedisclosed system include a power converter, such as a DC-DC converterelectrically connected to the IDC. An optical fiber management device,such as an optical splice device, is situated in the interior of thehousing and configured to receive the optical fiber. A media board isincluded in some embodiments that is configured to convert opticalsignals to electrical signals. In some implementations, the IDC includesa housing with a fiber pass-through groove configured to route opticalfibers through the housing of the IDC, and first and second conductorgrooves are situated on either side of the fiber pass-through groove toreceive first and second conductors.

Another aspect of the present disclosure relates to a powered fiberoptic system. The powered fiber optic system includes a first locationincluding a power source and fiber optic network access and a pluralityof active devices remotely positioned with respect to the firstlocation. The powered fiber optic system further includes a plurality ofhybrid cables routed from the first location toward the active devices.The hybrid cables include optical fibers for transmitting opticalsignals and electrical conductors for carrying power. The powered fiberoptic system further includes interface devices mounted adjacent to theactive devices for providing interfaces between the hybrid cables andthe active devices. The interface devices include electrical powermanagement circuitry positioned within the closure for providingDC-to-DC voltage conversion within the closure and also include circuitprotection circuitry for providing current surge protection.

A further aspect of the present disclosure relates to an interfacedevice for providing an interface between a hybrid cable and an activedevice. The interface device includes a closure adapted for outsideenvironmental use and a cable anchoring structure for securing a hybridcable to the closure. The hybrid cable is configured to carry bothelectrical power and optical signals. The interface device also includeselectrical power management circuitry positioned within the closure forproviding DC-to-DC voltage conversion within the closure. The electricalpower management circuitry is customizable to output one of a pluralityof different DC voltage levels such that the DC output level can bematched with a power requirement of the active device. The interfacedevice also includes electrical protection circuitry positioned withinthe closure and an output configuration for outputting power andcommunications signals from the interface device to the active device.The output configuration has a format that is customizable andselectable from a plurality of formats that include all of the followingformats: a) a power over Ethernet format or a power over Ethernet plusformat; and b) a format including one or more optical fibers for theoptical signals and separate electrical conductors for power.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a system diagram showing an example distribution of wirelesscoverage areas deployed using a power and optical fiber interface systemin accordance with principles of the present disclosure.

FIG. 2 is a transverse cross-sectional view of a power/optical fiberhybrid cable in accordance with principles of the present disclosure.

FIG. 3 is a perspective view of a portion of the hybrid cable of FIG. 2with electrically conductive portions of the cable showing separatedfrom a central optical fiber portion of the cable.

FIG. 4 is a plan view of the hybrid cable of FIGS. 2 and 3 with theelectrically conductive portions of the hybrid cable trimmed relative tothe central fiber optic portion of the hybrid cable.

FIG. 5 is a transverse cross-sectional view of another power/opticalfiber hybrid cable in accordance with principles of the presentdisclosure.

FIG. 6 is a block diagram conceptually illustrating aspects of acommunication and power distribution system in accordance withprinciples of the present disclosure.

FIG. 7 is a top view of an interface device in accordance withprinciples of the present disclosure.

FIG. 8 is a perspective view of the interface device shown in FIG. 7 .

FIG. 9 is a partial top view of the interface device shown in FIG. 7 ,illustrating aspects of an insulation displacement connector (IDC) in anopen position.

FIG. 10 is another partial top view of the interface device shown inFIG. 7 , illustrating aspects of the IDC in a closed position.

FIG. 11 is a perspective view of the interface device shown in FIG. 7 ,illustrating an embodiment that includes an optical splice device.

FIG. 12 is a top view of the interface device shown in FIG. 11 .

FIG. 13 is a top view of the interface device shown in FIG. 7 ,illustrating an embodiment that includes a media board.

FIG. 14 is a circuit diagram illustrating an example power conditioningcircuit.

FIG. 15 shows a system in accordance with the principles of the presentdisclosure having a rack mounted power supply.

FIG. 16 shows a hybrid cable system in accordance with the principles ofthe present disclosure.

DETAILED DESCRIPTION

In the following Detailed Description, reference is made to theaccompanying drawings, which form a part hereof, and in which is shownby way of illustration specific embodiments in which the invention maybe practiced. In this regard, directional terminology, such as top,bottom, front, back, etc., is used with reference to the orientation ofthe Figure(s) being described. Because components of embodiments can bepositioned in a number of different orientations, the directionalterminology is used for purposes of illustration and is in no waylimiting. It is to be understood that other embodiments may be utilizedand structural or logical changes may be made without departing from thescope of the present invention. The following detailed description,therefore, is not to be taken in a limiting sense.

FIG. 1 shows a system 10 in accordance with the principles of thepresent disclosure for enhancing the coverage areas provided by cellulartechnologies (e.g., GSM, CDMA, UMTS, LTE, WiMax, WiFi, etc.). The system10 includes a base location 11 (i.e., a hub) and a plurality of wirelesscoverage area defining equipment 12 a, 12 b, 12 c, 12 d, 12 e and 12 f(sometimes collectively referred to as equipment 12 herein) distributedabout the base location 11. In certain examples, the base location 11can include a structure 14 (e.g., a closet, hut, building, housing,enclosure, cabinet, etc.) protecting telecommunications equipment suchas racks, fiber optic adapter panels, passive optical splitters,wavelength division multiplexers, fiber splice locations, optical fiberpatching and/or fiber interconnect structures and other active and/orpassive equipment. In the depicted example, the base location 11 isconnected to a central office 16 or other remote location by a fiberoptic cable such as a multi-fiber optical trunk cable 18 that provideshigh band-width two-way optical communication between the base location11 and the central office 16 or other remote location. In the depictedexample, the base location 11 is connected to the wireless coverage areadefining equipment 12 a, 12 b, 12 c, 12 d, 12 e and 12 f by hybridcables 20. The hybrid cables 20 are each capable of transmitting bothpower and communications between the base location 11 and the wirelesscoverage area defining equipment 12 a, 12 b, 12 c, 12 d, 12 e and 12 f.

The wireless coverage area defining equipment 12 a, 12 b, 12 c, 12 d, 12e and 12 f can each include one or more wireless transceivers 22. Thetransceivers 22 can include single transceivers 22 or distributed arraysof transceivers 22. As used herein, a “wireless transceiver” is a deviceor arrangement of devices capable of transmitting and receiving wirelesssignals. A wireless transceiver typically includes an antenna forenhancing receiving and transmitting the wireless signals. Wirelesscoverage areas are defined around each of the wireless coverage areadefining equipment 12 a, 12 b, 12 c, 12 d, 12 e and 12 f. Wirelesscoverage areas can also be referred to as cells, cellular coverageareas, wireless coverage zones, or like terms. Examples of and/oralternative terms for wireless transceivers include radio-heads,wireless routers, cell sites, wireless nodes, etc.

In the depicted example of FIG. 1 , the base location 11 is shown as abase transceiver station (BTS) located adjacent to a radio tower 24supporting and elevating a plurality the wireless coverage area definingequipment 12 a. In one example, the equipment 12 a can define wirelesscoverage areas such as a macrocells or microcells (i.e., cells eachhaving a coverage area less than or equal to about 2 kilometers wide).The wireless coverage area defining equipment 12 b is shown deployed ata suburban environment (e.g., on a light pole in a residentialneighborhood) and the equipment 12 c is shown deployed at a roadsidearea (e.g., on a roadside power pole). The equipment 12 c could also beinstalled at other locations such as tunnels, canyons, coastal areas,etc. In one example, the equipment 12 b, 12 c can define wirelesscoverage areas such as microcells or picocells (i.e., cells each havinga coverage area equal to or less than about 200 meters wide). Theequipment 12 d is shown deployed at a campus location (e.g., auniversity or corporate campus), the equipment 12 e is shown deployed ata large public venue location (e.g., a stadium), and the equipment 12 fis shown installed at an in-building or near-building environment (e.g.,multi-dwelling unit, high rise, school, etc.). In one example, theequipment 12 d, 12 e, and 12 f can define wireless coverage areas suchas microcells, picocells, or femtocells (i.e., cells each having acoverage area equal to or less than about 10 meters wide).

The wireless coverage area defining equipment 12 are often located inareas without power outlets conveniently located. As noted above, thehybrid cable 20 provides both power and data to the equipment 12. FIG. 2is a transverse cross-sectional view taken through an example of one ofthe hybrid cables 20 of FIG. 1 . Hybrid cable 20 includes an outerjacket 200 having a transverse cross-sectional profile that defines amajor axis 202 and a minor axis 204. The outer jacket has a height Hmeasured along the minor axis 204 and a width W measured along the majoraxis 202. The width W is greater than the height H such that thetransverse cross-sectional profile of the outer jacket 200 is elongatedalong the major axis 202.

The outer jacket 200 can include a left portion 206, a right portion 208and a central portion 210. The left portion 206, the right portion 208and the central portion 210 can be positioned along the major axis 202with the central portion 210 being disposed between the left portion 206and the right portion 208. The left portion 206 can define a leftpassage 212, the right portion 208 can define a right passage 214 andthe central portion 210 can define a central passage 216. The passages212, 214 and 216 can have lengths that extend along a centrallongitudinal axis 218 of the cable 20 for the length of the cable. Aleft electrical conductor 220 is shown positioned within the leftpassage 212, a right electrical conductor 222 is shown positioned withinthe right passage 214 and at least one optical fiber 224 is shownpositioned within the central passage 216. Certain embodiments includefrom 1 to 12 fibers 224, for example. The left electrical conductor 220,the right electrical conductor 222 and the optical fiber 224 havelengths that extend along the central longitudinal axis 218 of the cable20.

Still referring to FIG. 2 , the hybrid cable 20 includes a leftpre-defined tear location 226 positioned between the central portion 210and the left portion 206 of the outer jacket 200, and a rightpre-defined tear location 228 positioned between the central portion 210and the right portion 208 of the outer jacket 200. The left pre-definedtear location 226 is weakened such that the left portion 206 of theouter jacket 200 can be manually torn from the central portion 210 ofthe outer jacket 200. Similarly, the right pre-defined tear location 228is weakened such that the right portion 208 of the outer jacket 200 canbe manually torn from the central portion 210 of the outer jacket 200.The left pre-defined tear location 226 is configured such that the leftportion 206 of the outer jacket 200 fully surrounds the left passage 212and the central portion 210 of the outer jacket 200 fully surrounds thecentral passage 216 after the left portion 206 of the outer jacket 200has been torn from the central portion 210 of the outer jacket 200. Inthis way, the left electrical conductor 220 remains fully insulated andthe optical fiber 220 remains fully protected after the left portion 206has been torn from the central portion 210. The right pre-defined tearlocation 228 is configured such that the right portion 208 of the outerjacket 200 fully surrounds the right passage 214 and the central portion210 of the outer jacket 200 fully surrounds the central passage 219after the right portion 208 of the outer jacket 200 has been torn fromthe central portion 210 of the outer jacket 200. In this way, the rightelectrical conductor 222 remains fully insulated and the optical fiber224 remains fully protected after the right portion 208 has been tornfrom the central portion 210.

FIG. 3 shows the hybrid cable 20 with both the left portion 206 and theright portion 208 torn away from the central portion 210. In thisconfiguration, both the left electrical conductor 220 and the rightelectrical conductor 222 are fully insulated by their corresponding leftand right portions 206, 208. Additionally, the central portion 210 has arectangular transverse cross-sectional shape that fully surrounds thecentral passage 216 so as to protect the optical fiber or fibers 224.

It will be appreciated that the left and right electrical conductors220, 222 have a construction suitable for carrying electricity. It willbe appreciated that the electrical conductors can have a solid orstranded construction. Example sizes of the electrical conductorsinclude 12 gauge, 16 gauge, or other sizes.

The outer jacket 200 is preferably constructed of a polymeric material.In one example, the hybrid cable 20 and the outer jacket 200 are plenumrated. In certain examples, the outer jacket 200 can be manufactured ofa fire-retardant plastic material. In certain examples, the outer jacket200 can be manufactured of a low smoke zero halogen material. Examplematerials for the outer jacket include polyvinyl chloride (PVC),fluorinated ethylene polymer (FEP), polyolefin formulations including,for example, polyethylene, and other materials.

The central passage 216 can contain one or more optical fibers 224. Incertain examples, the optical fibers 224 can be coated optical fibershaving cores less than 12 microns in diameter, cladding layers less than240 microns in diameter, and coating layers less than 300 microns indiameter. It will be appreciated that the core and cladding layerstypically include a silica based material. In certain examples, thecladding layer can have an index of a refraction that is less than theindex of refraction of the core to allow optical signals that aretransmitted through the optical fibers to be confined generally to thecore. It will be appreciated that in certain examples, multiple claddinglayers can be provided. In certain examples, optical fibers can includebend insensitive optical fibers having multiple cladding layersseparated by trench layers. In certain examples, protective coatings(e.g., a polymeric material such as actelate) can form coating layersaround the cladding layers. In certain examples, the coating layers canhave diameters less than 300 microns, or less than 260 microns, or inthe range of 240 to 260 microns. In certain examples, the optical fibers224 can be unbuffered. In other examples, the optical fibers can includea tight buffer layer, a loose buffer layer, or a semi-tight bufferlayer. In certain examples, the buffer layers can have an outer diameterof about 800 to 1,000 microns. The optical fibers can include singlemode optical fibers, multi-mode optical fibers, bend insensitive fibersor other fibers. In still other embodiments, the optical fibers 224 canbe ribbonized.

As shown at FIG. 4 , the left and right portions 206, 208 can be trimmedrelative to the central portion 210 after the left and right portions206, 204 have been torn away from the central portion 210. In thisconfiguration, the central portion 210 extends distally beyond the endsof the left and right portions 206, 208. In certain examples, insulationdisplacement connectors can be used to pierce through the jacketmaterials of the left and right portions 206, 208 to electricallyconnect the left and right electrical connectors 220, 222 to anelectrical power source, ground, active components or other structures.It will be appreciated that the optical fibers 224 can be connected toother fibers with mechanical or fusion splices, or directly terminatedwith optical connectors. In other examples, connectorized pigtails canbe spliced to the ends of the optical fibers 224.

Referring back to FIG. 2 , the outer jacket 200 includes a top side 230and a bottom side 232 separated by the height H. As depicted, the topand bottom sides 230, 232 are generally parallel to one another. Each ofthe left and right pre-defined tear locations 226, 228 includes an upperslit 234 that extends downwardly from the top side 230, a lower slit 236that extends upwardly from the bottom side 232 and a non-slitted portion238 positioned between the upper and lower slits 234, 236. In oneexample embodiment, the upper and lower slits 234, 236 are partiallyre-closed slits. In the depicted embodiment, the left and rightpre-defined tear locations 226, 228 also include jacket weakeningmembers 240 that are imbedded in the non-slitted portions 238. By way ofexample, the jacket weakening members 240 can include strands,monofilaments, threads, filaments or other members. In certain examples,the jacket weakening members 240 extend along the central longitudinalaxis 218 of the cable 20 for the length of the cable 20. In certainexamples, the jacket weakening members 240 are aligned along the majoraxis 202. In certain examples, the upper and lower slits 230, 236 aswell as the jacket weakening member 240 of the left pre-defined tearlocation 226 are aligned along a left tearing plane PL that is orientedgenerally perpendicular relative to the major axis 202. Similarly, theupper and lower slits 234, 236 as well as the jacket weakening member240 of the right pre-defined tear location 228 are aligned along a righttearing plane PR that is oriented generally perpendicular with respectto the major axis 202.

Referring again to FIG. 2 , the hybrid cable 20 can include a tensilestrength structure 242 that provides tensile enforcement to the hybridcable 20 so as to prevent tensile loads from being applied to theoptical fibers 224. In certain embodiments, the tensile strengthstructure 242 can include reinforcing structures such as Aramid yarns orother reinforcing fibers. In still other embodiments, the tensilestrength structure 242 can have an oriented polymeric construction. Instill other examples, a tensile strength structure 242 can include areinforcing tape. In certain examples, the reinforcing tape can bebonded to the outer jacket 200 so as to line the central passage 216. Incertain examples, no central buffer tube is provided between the opticalfibers 224 and the tensile reinforcing structure 242. In certainexamples, the tensile strength structure 242 can include a reinforcingtape that extends along the length of the hybrid cable 20 and haslongitudinal edges/ends 244 that are separated so as to define a gap 244therein between. In use, the tensile strength member 242 can be anchoredto a structure such as a fiber optic connector, housing or otherstructure so as to limit the transfer of tensile load to the opticalfibers 224. It will be appreciated that the tensile strength structure242 can be anchored by techniques such as crimping, adhesives,fasteners, bands or other structures.

FIG. 5 shows an alternative hybrid cable 20′ having the sameconstruction as the hybrid cable 20 except two tensile strengthstructures 242A, 242B have been provided within the central passage 216.Tensile strength members 242A, 242B each include a tensile reinforcingtape that is bonded to the central portion 210 of the outer jacket 200.The tensile strength members 242A, 242B can include portions thatcircumferentially overlap one another within the central passage 216. Incertain examples, by stripping away an end portion of the centralportion 210, the tensile strength structures 242A, 242B can be exposedand readily secured to a structure such as a fiber optic connector, apanel, a housing or other structure. In one example, the tensilestrength structures 242A, 242B can be crimped, adhesively secured orotherwise attached to rods (e.g., epoxy rods reinforced with fibers)that are in turn secured within a ruggedized fiber optic connector suchas the fiber optic connector disclosed at U.S. Pat. No. 7,744,288 whichis hereby incorporated by reference in its entirety, or the fiber opticconnector disclosed at U.S. Pat. No. 7,918,609, which is herebyincorporated by reference in its entirety.

As noted above, the electrical conductors 220, 222 could be 12 gauge(AWG) or 16 gauge, for example. In certain examples, a 12 gaugeconductor 220, 220 provides up to 1175 meter reach at 15 W, and a 750meter reach for 25 W devices. The 16 gauge implementations can providereduced cost for shorter reach applications or lower power devices, forexample.

Providing power to remote active devices such as the wireless coveragearea defining equipment 12 is often difficult and expensive. Providingrequired power protection and backup power further complicates poweringsuch remote devices. Optical Network Terminals (ONT's) and Small Celldevices (such as picocells and metrocells) have “similar” powerrequirements. For example, 25W, 12 VDC or 48 VDC devices are common,although variations occur. FIG. 6 conceptually illustrates an example ofa communication signal and power distribution system 300 in accordancewith aspects of the present disclosure. Among other things, the system300 provides a simple, “universal” connection of the optical fiber 224and electrical conductors 220,222 of the hybrid cable 20 to theequipment 12.

The system 300 includes a fiber patch panel 302 that terminates opticalfibers carrying signals to be distributed to the desired wirelesscoverage area defining equipment 12 via the optical fibers 224 of thehybrid cables 20. A power supply 304 connects to the conductors 220, 222of the desired hybrid cable 20. In some examples, the power supply 304receives 120/220 VAC and provides 48 VDC nominal. In some embodiments,the fiber patch panel 302 and power supply 304 are rack mounted.

A first end 306 of the hybrid cable 20 is connected to the appropriateoptical fibers from the fiber patch panel 302 and to the power supply304. A second, distant end 308 of the cable 20 is connected to aninterface device 310. The interface device is connected to the wirelessequipment 12, either directly or through a media converter 312. Examplesof the interface 310 provide simplified termination of the hybrid cable20, allowing factory or field installation. In some embodiments, a DC-DCconverter provides the desired voltage level for the particular device12 to which it is connected and compensates for IR loss across variablelink lengths.

FIGS. 7-13 illustrate various views of embodiments of the interfacedevice 310. The interface device 310 includes a body 320 having anexterior 322 and an interior 324. A cover 326 is connected to the body320 by a hinge 328 such that the interface device 310 can be opened toexpose the interior 324 for access by an operator. A mounting bracket340 extends from the body 320 for mounting the interface device 310 asdesired using screws or bolts, for example. In one example, theinterface device 310 defines footprint dimensions of about 55 mm×125mm×190 mm.

A cable clamp 342 cooperates with the body 320 to fix the hybrid inputcable 20 and an output cable 344 to the interface device 310 at a cableinlet 350 and a cable outlet 352, respectively. As noted above, thehybrid cable 20 includes electrical conductors 220, 220 for supplyingpower to the interface device 310, and ultimately the remote device 12.In the illustrated examples, the interface device 310 includes aninsulation displacement connector (IDC) 360 situated in the interior 324of the interface device body 320 for connecting the conductors 220, 220to the interface device 310. Generally, an IDC (also sometimes referredto as insulation displacement termination and insulation piercingconnector) is an electrical connector that connects to one or moreconductors of an insulated conductor by a connection process that forcesa selectively sharpened blade or blades through the insulation tocontact the conductor, eliminating the need to strip the insulationbefore connecting. Further, the connector blades cold weld to theconductors to form a gas-tight connection.

FIGS. 9 and 10 illustrate the IDC 360 in closed and open positions,respectively. As shown in FIG. 3 and discussed in conjunction therewithabove, the hybrid cable 20 is configured such that the left portion 206and the right portion 208 can be torn away from the central portion 210.In this configuration, both the left electrical conductor 220 and theright electrical conductor 222 are fully insulated by theircorresponding left and right portions 206, 208. Referring to FIG. 10 ,the IDC 360 includes a housing 358 with first and second conductorgrooves 362, 364 positioned on either side of a fiber pass-throughgroove 366. Correspondingly, the electrical conductors 220, 222 of thehybrid cable 20 are situated on either side of the central portion 210containing the optical fibers 224.

The conductors 220, 222 are received by the corresponding conductorgrooves 362, 364, and insulator clamping ribs 368 are situated to pressagainst the jacket 200 to hold the hybrid cable 20 in place. The IDC 360includes a cover 370 hingedly connected to the housing 358 that whenclosed presses IDC terminals 372 against the conductors 220, 222 andthrough the left portion 206 and the right portion 208 of the outerjacket 200 to make an electrical connection with the conductors 220,222. The illustrated IDC terminals 372 are angled to provide a gas-tightconnection. In the illustrated example, the left and right portions 206,208 are trimmed such that the conductors 220,222 extend beyond the IDCterminals 372 but remain within the housing 358 of the IDC 360.

In other embodiments, the IDC is configured in a “pass-through” powerarrangement, wherein the terminals 372 pierce the left and rightportions 206, 208 to contact the conductors 220,222, but the left andright portions 206, 208 are not trimmed so they extend through the IDC360 to be routed to equipment 12 or another interface device 310, suchas via the cable outlet 352.

In the illustrated example, a power converter 376, such as a DC-DCvoltage converter, is situated in the interior 324 of the base 320 andelectrically connected to the IDC 360 so as to electrically connect theconductors 220, 220 of the hybrid cable 20 to the power converter 376via the IDC 360. Thus, power entering the interface device 310 via thehybrid cable 20 can be conditioned and/or converted to the desired levelfor the wireless coverage area defining equipment 12 to which theinterface device 310 connects. The power converter 376 is connectable tothe output cable 344 to route the conditioned/converted power from theinterface device 310 to the desired wireless equipment 12. For instance,conductors of the output cable 344 could connect directly to the powerconverter 376 using screw terminals 378 thereon. In alternativeembodiments, the power converter 376 can be omitted or bypassed if thepower received by the interface device 310 is appropriate for theparticular end device 12. Further power connection arrangements arediscussed herein below.

The optical fibers 224 from the hybrid cable 20 are received by thecentrally positioned fiber pass-through groove 366 to route the opticalfibers 224 through the housing 358 of the IDC 360. The fibers 224 extendfrom the housing 358 and are routed along the perimeter of the interior324 of the interface device 310. In some embodiments, the optical fibers324 are routed through the interior 324 directly to the cable outlet352, along with a separate power output cable. More typically, thefibers 324 would be routed to a fiber management device 380. In theillustrated example, fiber guides 374 are situated in the corners of theinterior 324 for routing the optical fibers 324 in the interface devicewhile maintaining a desired bend radius. In certain implementations, theoptical fibers 324 are thus received at the cable inlet 350, routedthrough the IDC housing 358 and the interior 324 of the interface devicebody 320 to the fiber management device 380.

FIGS. 11 and 12 illustrate an example of the interface device 310wherein the fiber management device 380 includes an optical splicedevice for making a mechanical or fusion splice, for example. Theillustrated fiber management device 380 thus includes furcation tubes382 situated on splice holders 384. In other implementations, otherfiber optic management devices such as fiber optic connectors areprovided. A strength member termination 386 is further provided in theembodiment illustrated in FIGS. 11 and 12 . The optical fibers 224 canthus be spliced, for example, to a fiber optic pig tail and routed tothe cable outlet 352. In some examples, the output cable 244 is also ahybrid cable including optical fibers that are spliced to the fibers 224using the fiber management device 380, and conductors that receive powerfrom the power converter 376.

FIG. 13 illustrates another embodiment where the fiber management device380 includes a media board 390 that converts optical signals receivedvia the optical fibers 224 to electrical signals. A fiber opticconnector 392, such as an LC duplex input connector, is connected to themedia board 390 to terminate the optical fibers routed through theinterior 324 of the interface device 310 and receive optical signalstherefrom. The media board 390 is electrically connected to the IDC 360,either directly, or as in the illustrated embodiment, via the powerconverter 376. In this manner, the media board is powered by power fromthe conductors 220,222 terminated by the IDC 360. Additionally, in someembodiments, the media board 390 connects output power and electricalcommunication signals to a power over Ethernet (PoE) connection. In suchembodiments, the output cable 344 is a standard RJ-45 datapower cablethat connects to a PoE jack 394 on the media board 390. The RJ-45 cablecan then be connected to the desired wireless coverage area definingequipment 12 to provide both communication signals and power thereto.

Some embodiments, for example, include 12 fibers 224 situated in thecentral passage 216. Typically, two optical fibers 224 are terminated ina given interface device 310. Since the two fibers 224 carrying signalsfor the desired wireless equipment 12 are to be terminated in theinterface device 310, they are cut downstream of the interface device310. A slit can be cut in the central portion 216 providing an openingthrough which the desired fibers 224 can be pulled from the centralportion and routed to the fiber management device 380. The remainingoptical fibers 224 remain intact within the central portion 216, and canbe passed through the interface device 310 to another device, forexample.

The power converter 276 provides DC/DC conversion, for example, as wellas other power management functions such as circuit overload protection,mains cross protection, lightning protection, etc. In one particularembodiment, a 30 W, 12V output DC-DC converter from CUI Inc. ofTualatin, OR (PN VYC30W-Q48-S12-T) is used. Other DC-DC converters maybe employed based on electrical requirements, packaging, etc. In someimplementations, a conditioning circuit is integrated into the interface310 to minimize voltage ripple. FIG. 14 shows an example of a typicalconditioning circuit 400. In further examples, overvoltage protection,such as a gas-tube, is incorporated between the IDC terminals and DC-DCconverter input.

Referring back to FIG. 6 , the fiber patch panel 302 can receive canreceive optical signals from a remote location via a fiber optic trunkcable. Optical fibers of the trunk cable 110 can be separated at afan-out device, or optical power splitters or wavelength divisionmultiplexers can be used to split optical communications signals fromthe trunk cable to multiple optical fibers. The fibers can be routed tothe patch panel 302, and then to a desired one of the hybrid cables 20,along with electrical power from the power supply 304. In one example,the power supply 304 receives 120 volt or 220 volt alternating current.In one example, power supply 302 includes an AC/DC converter thatconverts the electrical power from alternating current to directcurrent. The power supply 304 converts the electrical power from thefirst voltage (e.g., 120v or 220v) to a second voltage that is less thanthe first voltage. In one example, the second voltage is less than orequal to 60 volts and 100 Watts such that the output voltage complieswith NEC Class II requirements.

The hybrid cable 20 can be used to transmit electrical power and opticalcommunication signals from the fiber patch panel 302 and power supply304 located at a first to the wireless equipment 12 located at a secondlocation. The first end 306 of the hybrid cable 20 can include a firstinterface for connecting the hybrid cable to electrical power and fiberoptic communication at a connector, and the second end 308 of the hybridcable 20 is received at the cable inlet 350 of the interface device 310.The power converter 376 of the interface device 310 converts electricalpower carried by the hybrid cable 20, for example, to a direct currentthird voltage that is less than the second voltage. In one example, thethird voltage corresponds to an electrical voltage requirement of thedevice 12. In one example, the third voltage is 12V, 24V or 48V.

In some implementations, a converter 312 is associated with theequipment 12 for converting optical signals to electrical signals. Insuch implementations, the optical fibers and power are provided from theinterface device 310 to the converter 312, which provides power andcommunication signals to the equipment 12. In other implementations, theinterface device 310 converts the optical signals to electrical signalsusing the media board 390, and provides power and electricalcommunication signals to the equipment 12.

Aspects of the present disclosure relate to powered fiber cable systemscapable of simultaneously powering and communicating with wirelesscoverage area defining equipment (e.g., transceivers, wireless routers,WiFi access points/WiFi hot spots, small cell devices, or like devices).The powered fiber cable system can also be used to power and communicatewith other devices such as digital signage, high definition surveillancecameras, and like devices. Moreover, powered fiber cable systems inaccordance with the principles of the present disclosure can beincorporated into fiber optic networks (e.g., fiber-to-the-home (FTTH),fiber-to-the-premises (FTTP, fiber-to-the-anything (FTTX)) to provideback-up power or primary power to optical network terminals (ONT)including electronics for providing optical-to-electrical conversion ator near a subscriber location. By providing back-up power using apowered fiber cable system in accordance with the principles of thepresent disclosure, battery back-ups at the optical network terminalscan be eliminated. Powered fiber cable systems in accordance with theprinciples of the present disclosure are particularly well suited forsupporting active devices at outdoor locations where power is notreadily available. However, powered fiber cable systems in accordance ofthe principles of the present disclosure can also be used to supportindoor applications such as in local area networks where power and fiberare provided to desk-top locations (e.g., fiber-to-the-desk (FTTD)).Other applications for powered fiber cable systems in accordance withthe principles of the present disclosure relate to power-over-Ethernetextensions (PoE or PoE+).

Aspects of the present disclosure relate to systems that provide a “rackto device” vision for both powering and communicating with activedevices such as small cell devices, ONT's, WiFi hot spots, digitalsignage, surveillance cameras or like devices in one cable system. FIG.15 shows an example powered fiber cable system 400 in accordance withthe principles of the present disclosure. The powered fiber cable system400 includes a rack 402 positioned at a location where power (e.g., apower system\grid that typically provides AC power such as a mains powersystem) and fiber network are available. Such locations where power andfiber optic network communications are available can be referred to ashead ends. In certain examples, the power locations (i.e., head ends)can be co-located at a cell site base station, a base station on abuilding top, in a telecom closet or data center or anywhere where powerand access to a fiber optic network are available. As shown at FIG. 15 ,a patch panel 404 is mounted on the rack 402. The patch panel 404 iscoupled to a fiber optic network. For example, optical fibers opticallycorresponding to fiber optic distribution or feed cables can beconnectorized and plugged into fiber optic adapters supported at thepatch panel 404. The rack 402 is also shown supporting a power supplyunit 406 that in certain examples provides a DC output of 48 volts orless.

In one example, the power supply can include a power express class IIpower converter shelf manufactured by General Electric. The power supplycan include and AC/DC transformer for transforming alternating current(AC) from a mains power supply into DC power for distribution toremotely located active devices. In certain examples, the power supply406 can power up to 32 hybrid cables 20 in a modular design with fourmodules and eight cables per module. In certain examples, the powersupply is configured to output relatively low voltage DC current (e.g.,less than or equal to 48 volts DC). In certain examples, the powersource is National Electric Code (NEC) class 2 (as specified by Article725) and Safety Extra Low Voltage (SELV) compliant. In certain examples,the voltage between any two conductors should not exceed 60 volts DCunder normal operating conditions. In certain examples, the power supplyis limited to 100 VA. Such low voltage circuits are advantageous becauseelectricians are not required to install such systems, such systems areinherently safe because of the low voltage limits, and such systems canbe installed in a conduit-free manner. In certain examples, the powersupply can also include circuit protection electronics such as gasdischarge tubes, metal oxide varistor components and transient voltagesuppression structures/diodes.

As shown at FIG. 15 , the patch panel 404 and the power supply 406 areboth rack mounted. Optical communication lines from the patch panel 404and power lines from the power source 406 are coupled to hybrid cables20 routed to universal interface devices 310 that support active devicessuch as a picocell 408, a metrocell 410, a femtocell 412 and an ONT 414.The ONT 414 is shown connected to the corresponding interface device 310by a power line 415 and a separate fiber line 417. The picocell 408,metrocell 410 and femtocell 412 are coupled to their correspondinginterface devices 310 by power lines 419 and two fiber lines 421, 423.In other examples, the fiber lines 421, 423 can be replaced with twistedpair conductors for carrying electrical signals in cases where opticalto electrical signal conversion occurs at the interface device 310.

Further aspects of the present disclosure relate to a remote interfacedevice (e.g., interface device 310 that is remote from the power supply)for providing an interface between a hybrid cable and a remote activedevice, the interface device including a closure that houses circuitryfor providing electrical power management and including circuitprotection electronics. It will be appreciated that the circuitry withinthe closure is adapted for providing an effective interface between ahybrid cable (e.g., hybrid cable 20) and a remote active device. Incertain examples, the closure is designed for outdoor environmental useand includes an environmentally sealed construction. In certainexamples, the electrical power management circuitry eliminates the needfor line power system design. For example, the electrical powermanagement circuitry can include a DC-to-DC converter suitable forconverting power carried by one of the hybrid cables 20 to a voltage andpower level compatible with an active device intended to be powered withpower from the hybrid cable 20. In certain examples, the DC-to-DCconverter can increase the voltage of the power carried by the hybridcable 20 to a level compatible with the active device powered by thehybrid cable. In certain examples, the increase in voltage provided bythe DC-to-DC converter compensates for voltage loss that may occur overthe length of the hybrid cable. In certain examples, the DC-to-DCconverter raises the voltage level to 12 volts, 24 volts or 48 volts. Incertain other examples, the DC-to-DC converter decreases the voltagelevel to a level compatible with the active device intended to bepowered by the hybrid cable. In certain examples, the power is convertedso as to become compatible with a watt device, a 30 watt device, or a 45watt device. In certain examples, the closure also houses anoptical-to-electrical converter that converts optical signals from thehybrid cable to electrical signals that are transmitted to the activedevice. In certain examples, the electrical signals and the power can betransmitted from the interface device to the active device by a twistedpair Ethernet cable so as to provide power-over-Ethernet orpower-over-Ethernet-plus connectivity.

As indicated above, the closure of the interface device can enclosecircuit protection electronics. For example, the circuit protectionelectronics can include primary electrical protection that may include agas discharge tube rated to at least 40 kAmp surgeover/voltageprotection. Such structure can provide protection with respect tolightning strikes and line cross-overs. The electrical protection canalso include secondary electrical protection that may be rated to 4.5kAmp and that may include metal oxide varistor components that couple toground in response to voltage surges. The electrical protection may alsoinclude tertiary protection that prevents voltage from rising above apredetermined level (e.g., 80 volts, or 100 volts). In certain examples,the tertiary protection can include a transient voltage suppressiondiode. In certain examples, fast acting fuses can be used.

Cables in accordance with the principles of the present disclosure canprovide power over relatively long distances. For example, using 12gauge conductors in the hybrid cable and using conversion circuitry inthe interface device that converts the optical signals and power to aPoE format, the system can provide 10 Watts of power over a length of3,000 meters, 15 Watts of power over 2,400 meters, 20 Watts of powerover 1,900 meters and 25 Watts of power over 1,600 meters. If power isprovided in a non-power over Ethernet format (e.g., via an M8 plug orother power lines separate from the communications lines), 30 watt powercan be provided up to 1,600 meters and 45 watt power can be provided upto 1,000 meters. A system that utilizes 16 gauge conductors and outputspower in a power over Ethernet format can provide 10 watts of power at1,200 meters, 15 watts of power at 960 meters, 20 watts of power at 760meters, and 25 watts of power at 640 meters. By not using a power overEthernet format and instead keeping the power separate from thecommunications via a separate power line, the 16 gauge wire can provide30 watts of power at 640 meters and 45 watts of power at 400 meters.

Aspects of the present disclosure relate to interface closures that canbe readily customized to meet customer requirements. In certainexamples, the closures can be environmentally sealed and can includeclamps for clamping hybrid cables such as the hybrid cable 20. Theclosures can also include power management circuitry such as powerconverters (e.g., DC-to-DC power converters). The power converters canbe customized to comply with the power requirements of the remote deviceintended to be powered by the customer. In certain examples, the powerconversion circuitry can be modular and modules providing differentlevels of conversion can be selected and plugged into the circuit boardof the closure to satisfy the customer requirement. For example, powerconverters capable of outputting 12, 24 or 48 volts can be used. It willbe appreciated that the format of the power output from the interfaceclosure can also be customized to meet customer needs. For example, theinterface closure can be configured to output power and communicationsover a variety of formats such as: (a) power-over-Ethernet; (b)power-over-Ethernet-Plus; (c) separate power (e.g., via a cableterminated with an M8 plug or other configuration) and Ethernet lines(e.g., terminated with RJ45 connectors or other connectors); (d)separate fiber lines for communications and power lines for power (e.g.,terminated with M8 connectors or other power connectors); (e) a hybridcable having optical fibers for optical signals and electricalconductors for power that can be terminated with a hybrid connector orcan have separate fiber and power pigtails; or (f) a cable havingtwisted pair conductors for carrying communication signals and separateelectrical conductors for power that can be terminated by separateRJ-style connectors for communication signals and an M8 plug for poweror other connector arrangements. In the case where separate fiber linesare used, the fiber lines can be terminated with different styles offiber optic connectors such as LC connectors, SC connectors, or otherfiber optic connectors. In certain examples, the fiber optic connectorscan be ruggedized and can include environmental sealing as well astwists-to-lock fastening elements such as threaded fasteners orbayonet-style fasteners. In the case of Ethernet cable, standard RJ-45connectors or ruggedized RJ-45 connectors can be used. For pigtailscarrying only power, stranded or solid conductors can be used.Additionally, the power pigtails can be terminated with power connectorssuch as M8 connectors.

FIG. 16 shows a cable system 100 that can be used to transmit power andcommunications from a first location 102 to an active device 104 at asecond location 106. The second location 106 is remote from the firstlocation 102. In certain example, the first location 102 can be a baselocation and the active device 104 can include wireless coverage areadefining equipment. Examples of wireless coverage area definingequipment and locations where such equipment may be installed aredescribed above. Examples of other types of active devices includecameras such as high definition video cameras.

The first location 102 receives optical signals from a remote location108 via a fiber optic trunk cable 110. Optical fibers of the trunk cable110 can be separated at a fan-out device 111 at the first location.Alternatively, optical power splitters or wavelength divisionmulti-plexers can be used to split optical communications signals fromthe trunk cable 110 to multiple optical fibers. The fibers can be routedto a patch panel 112 having fiber optic adapters 114 (i.e., structuresfor optically and mechanically interconnecting two fiber opticconnectors 115). The first location 102 can also include a combinedpower/communication panel 116 having fiber optic adapters 117 pairedwith power adapters 118 (i.e., ports). Connectorized fiber optic patchcords 120 can be routed from the fiber optic adapters 114 to the fiberoptic adapters 117.

The first location 102 can receive electrical power from a main powerline 122. In one example the main power line 122 can be part of a mainspower system that provides 100-240 nominal volt alternating current(example frequencies include 50 and 60 Hertz). The first location 102can include a converter 124 for converting the electrical power from thefirst voltage (e.g., 100v, 120v, 220v, 230v, 240v etc. nominal voltage)to a second voltage that is less than the first voltage. In one example,the second voltage is less than or equal to 60 volts and less than orequal to 100 Watts such that the output voltage complies with NEC ClassII requirements. In one example, the converter 124 is an AC/DC converterthat converts the electrical power from alternating current to directcurrent. Connectorized power cords 126 can be used to route electricalpower having the second voltage from the converter 124 to the poweradapters 118. In certain examples, the combined power/communicationspanel 116 can include at least 18, 24, 30 or 32 fiber optic adapterspaired with corresponding power adapters 118. In certain examples, theconverter 124 is large enough to provide NEC Class II compliant powerthrough separate hybrid cables to at least 18, 24, 30 or 32 activedevices. Of course, converter having smaller capacities could be used aswell. Additionally, the converter 124 can be part of a voltageconversion package including overvoltage protection that providesprotection/grounding in the event of lightning strikes and main crosses.

A hybrid cable 20 can be used to transmit electrical power and opticalcommunication signals between the first and second locations 102, 106.The hybrid cable 20 can include an outer jacket 150 containing at leastone optical fiber 152 for carrying the optical communication signals andelectrical conductors 154 (e.g., wires such as ground and power wires)for transmitting the electrical power having the second voltage. Thehybrid cable 20 can include a first end 156 and a second end 158. Thefirst end 156 can include a first interface for connecting the hybridcable to electrical power and fiber optic communication at the firstlocation 102. In one example, the first interface can include a powerconnector 160 (e.g., a plug) that connects the electrical conductors 154to one of the connectorized power cords 126 at the power/communicationspanel 116. The power connector 160 can be plugged into the adapter 118and can be provided at a free end of a cord that extends outwardly fromthe outer jacket 150 at the first end of the hybrid cable 20. The cordcan contain the electrical conductors 154. The first interface can alsoinclude a fiber optic connector 162 (e.g., an SC connector, LCconnector, ST-style connector or other type of connector) that connectsthe optical fiber 152 to one of the patch cords 120. The fiber opticconnector 162 can plug into one of the fiber optic adapters 117 and canbe mounted at the free end of a cord that contains the optical fiber 152and extends outwardly from the outer jacket 150 at the first end of thehybrid cable 20.

The second end 158 of the hybrid cable 20 can include a second interfacefor connecting the hybrid cable 20 to the active device 104 such thatelectrical power is provided to the active device 104 and such thatfiber optic communication signals can be transmitted between the firstand second locations 102, 106. The second interface includes aninterface structure 164 including a power connection location 166 and acommunication connection location 168. In one example, the interfacestructure 164 includes a power converter 170 for converting electricalpower carried by the hybrid cable 20 to a direct current third voltagethat is less than the second voltage. In one example, the third voltagecorresponds to an electrical voltage requirement of the active device104. In one example, the power converter 170 is a DC/DC converter. Inone example, the third voltage is 12V, 24V or 48V. In examples where ACcurrent is transmitted by the hybrid cable 20, the power converter 124can be an AC/AC converter and the power converter 170 can be an AC/DCconverter. In certain examples, the interface structure 164 can includean optical-to-electrical converter for converting the communicationssignals carried by the optical fiber 152 from an optical form to anelectrical form. In other examples, optical-to-electrical conversion canbe performed by the active device 104 or can take place between theactive device 104 and the interface structure 164.

In one example, the interface structure 164 includes a converterinterface that allows power converters 170 with different conversionratios to interface and be compatible with the interface structure 164.The conversion ratio of the particular power converter 170 used can beselected based on factors such as the voltage requirement of the activedevice 104 and the length of the hybrid cable 20. The power converters170 can have a modular configuration can be installed within theinterface structure 168 in the field or in the factory. In one example,the power converters 170 can have a “plug-and-play” interface with theinterface structure. The modular configuration also allows the powerconverter 170 to be easily replaced with another power converter 170, ifnecessary. In certain examples, the interface structure 164 can includeovervoltage protection and grounding arrangements such as fuses, metaloxide varistors, gas tubes or combinations thereof.

In one example, the electrical power having the third voltage can beoutput to the active device 104 through the power connection location166. The power connection location 166 can include a power connector, apower port, a power cord or like structures for facilitating connectingpower to the active device 104. In one example, the power connectionlocation 166 can have a modular configuration that allows interfaceconnectors having different form factors to be used.

In one example, the communications signals can be transferred betweenthe hybrid cable 20 and the active device through the communicationconnection location 168. The communication connection location 168 caninclude a connector, a port, a cord or like structures for facilitatingconnecting to the active device 104. In one example, the communicationconnection location 168 can have a modular configuration that allowsinterface connectors having different form factors to be used. In thecase where the optical to electrical converter is provided within theinterface structure 164, the connection location can include electricalcommunication type connectors (e.g., plugs or jacks) such as RJ styleconnectors. In the case where the optical to electrical converter isprovided at the active device 104, the communication connection location168 can include fiber optic connectors and or fiber optic adapters(e.g., SC connectors/adapters; LC connectors/adapters, etc.). In certainexamples, ruggedized, environmentally sealed connectors/adapters can beused (e.g., see U.S. Pat. Nos. 8,556,520; 7,264,402; 7,090,407; and7,744,286 which are hereby incorporated by reference in theirentireties. It will be appreciated that when the active devices includewireless transceivers, the active devices can receive wireless signalsfrom the coverage area and such signals can be carried from the activedevices to the base station 11 via the hybrid cables. Also, the activedevices can covert signals received from the hybrid cables into wirelesssignals that are broadcasted/transmitted over the coverage area.

In one example, the second voltage is less than the first voltage andgreater than the third voltage. The third voltage is the voltagerequired by the active device at the second location. In one example,the second voltage is sufficiently larger than the third voltage toaccount for inherent voltage losses that occur along the length of thehybrid cable.

Various modifications and alterations of this disclosure may becomeapparent to those skilled in the art without departing from the scopeand spirit of this disclosure, and it should be understood that thescope of this disclosure is not to be unduly limited to the illustrativeexamples set forth herein.

What is claimed is:
 1. A powered fiber optic system comprising: a firstlocation including a power source and fiber optic network access; aplurality of active devices remotely positioned with respect to thefirst location; a plurality of hybrid cables routed from the firstlocation toward the active devices, the hybrid cables including opticalfibers for transmitting optical signals and electrical conductors forcarrying power; and interface devices mounted adjacent to the activedevices for providing interfaces between the hybrid cables and theactive devices, the interface devices including electrical powermanagement circuitry positioned within the closure for providingDC-to-DC voltage conversion within the closure, the interface devicesalso including circuit protection circuitry for providing current surgeprotection.